Wire drawing



y 1, 19 2 J. c. GARAND 2,290,176

WIRE DRAWING Filed Nov. 27, 1941 dmhn [l g d SHM ' Patented July 21,1942

UNITED STATES PATENT OFFICE WIRE DRAWING John C. Garand, Springfield, Mass. Application November 27, 1941, Serial No. 420,627

(Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) 2 Claims.

The invention described herein may be manufactured and used by'or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a wire drawing die and more particularly to a die that will not tear stock of tough material, such as stainless steel which tends to stick to dies of conventional type thereby causing such tearing.

The present application constitutes a CD11- tinuation in part of m co-pending U. S. application, Serial No. 241,820, filed Nov. 22, 1938.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawing in which:

The single figure of the drawing is a schematic elevational view of a die designed in accordance with my invention.

As shown in the drawing a pair of opposed die members I and H are mounted for rotation on spaced parallel shafts l2 and i3, respectively.

The die member I0 is formed with a cylindrical forming surface 14 and the die member H is formed with a centrally disposed cylindrical forming surface I5 bounded by opposed outwardly and inwardly directed symmetrically arranged beveled surfaces It beveled at angles more specifically referred to hereinafter.

A second pair of die members I1 and I8 have lower planar surfaces l9 and cylindrical forming surfaces 2|, 22, respectively, with upper beveled edges 23 interposed between the rollers l0 and II in symmetrical overlapped relation. The planar surfaces IQ of die members I! and I8 bearingly engage the beveled surfaces [6 of die I member II in parallel relation and similarly the beveled edges 23 of these die members are bearingly engaged by the surface 14 of die member H1 in parallel relation. The die members I1 and ii! are mounted for rotation on inclined axes 24 and 25 as shown in the drawing.

The axes of shafts 24 and 25 are arranged in the same plane as the axes of shafts l2 and i3 and the die members l0 and II are so disposed as to make the distance a from the axis of shaft H to the cylindrical forming surface I5 of die member'll substantially equal to the radius 1) of either die member I! or I8. I

The die opening formed by the forming surfaces l4, [5, 2| and 22 is trapezoidiform in cross section to form the stock being drawn into wire 26 of a similar section. I have found that when wire of proper trape'zoidiform section is coiled into a helical spring with the narrow edge of such section disposed on the interior of the spring being formed, that due to the compression of the metal in the proximity of this narrow edge and the tension of the metal on the outer or wide edge of the wire section the dimensions of the section will be substantially equalized resulting in a finished spring formed of wire substantially.

of its coils of substantially rectangular shape in cross section when coiled as above explained.

By the foregoing arrangement a die has been provided wherein the linear velocities of the die members acting upon the stock being drawn are of substantiall the same or only smalldifference wherebythe action thereof upon the stock is uniform eliminating tendency to tear the stock, and the die opening is maintained at substantially v the same cross sectional area as the die members rotate due to the inter-bearing relation shown in the drawing.

Having now described a present preferred embodiment of the invention, I claim:

1. A die for drawing wire embodying a first pair of die members comprising a first di'e member having a cylindrical forming surfaceand a second die member having a cylindrical forming surface of less width than said first recited cylindrical forming surface, said second die member also being provided with beveled surfaces extending outwardly and inwardly from the cylindrical forming {surface thereof in symmetrical relation, a pair of parallel shafts rotatably mounting the first and second die members with their forming surfaces in spaced parallel synnnetrically aligned relation, a second pair of die members each comprising cylindrical forming surfaces and planar lower surfaces arranged normally to the cylindrical forming surfaces, said second pair of die members each being formed with beveled edges extending upwardly and inwardly from the cylindrical forming surfaces thereof, a second pair of shafts having their axes in the plane of the axes of said first pair of shafts rotatably mounting the second pair of die members with the planar surfaces thereof in parallel bearing relation to the beveled surfaces respectively of the second die member and the beveled surfaces thereof in parallel bearing relation to the cylindrical surface of the first die member; whereby the forming surfaces of all of said die members cooperate to form a die opening of trapezoidiform in cross section.

2. A die for drawing wire embodying a first pair of die members comprising a first die member having a cylindrical forming surface and a second die member having a cylindrical forming surface of less width than said first recited cylindrical forming surface, said second die member also being provided with beveled surfaces extending outwardly and inwardly from the cylindrical forming surface thereof in symmetrical relation, a pair of parallel shafts rotatably mounting the first and second die members with their forming surfaces in spaced parallel symmetrically aligned relation with the distance from the axis of one shaft to the forming surface of the die member on the other shaft equal to a distance a, a secand pair of die members each comprising cylindrical forming surfaces a radius b=a and planar lower surfaces arranged normally to the cylindrical forming surfaces, said second pair of die members each being formed with beveled edges extending upwardly and inwardly from the cylindrical forming surfaces thereof, a second pair of shafts having their axes in the plane of the axes of said first pair of shafts rotatably mounting the second pair of die members with the planar surfaces thereof in parallel bearing relation to the beveled surfaces respectively of the second die member and the beveled surfaces thereof in parallel bearing relation to the cylindrical surface of the first die member; whereby the forming surfaces of all of said die members cooperate to form a die opening of trapezoidiform in cross section.

JOHN C. GARAND. 

